The present invention relates to a device for securing a two-layered knitted fabric to a support, for example a device used to secure a seat cover to a seat frame.
In the automobile industry the trend in automotive seat manufacturing is to no longer weave the seat covers and assemble them in a relatively labor-intensive process, but rather to manufacture them in finished form directly on a flat-bed knitting machine as a three-dimensional knitted fabric, so that no further assembly is needed. When the seat cover is manufactured on the knitting machine, it is of course desirable to knit the seat cover fastening areas that are used to secure the seat cover to the seat frame at the same time as the cover itself, so that no additional assembly work is required for the fasteners. One way to achieve this objective is recited in EP 0 484 370 A1, in which tubular sections are knitted on during the process in which the seat cover is knitted, without the need for a separate assembly step. However, such knitted-on parts substantially lengthen the machine operating times for the individual seat cover, since the rest of the cover cannot be knitted during the time these parts are being knitted. Of course, such seat covers are also suitable for freestanding furniture in offices or residences, in other words for stationary seating applications.
The object of the invention is to create a device for securing a two-layered knitted fabric to a support wherein said device permits the knitted fabric to be easily secured to the support without a substantial increase in the time and effort needed to manufacture the seat cover. This object is accomplished by the elements of claim 1. Preferred embodiments of the invention are recited in the dependent claims.
In the invention, a fastener that is used to secure the seat cover to the support is pulled in between the two layers of the seat cover. This fastener may, for example, be a welt or a hollow profile into which one end of a connector or fastener engages, while the other end of said connector or fastener is provided on or can be secured on the support. Said first fastener must always be more rigid than the knitted fabric itself so that it can thereby hold the knitted fabric flatter against the support. For example, the welt can be a relatively rigid plastic rod; however, it may also be embodied as a somewhat more rigid wire or a plastic cord in any given shape that can be inserted into an elongated pocket.
Second fasteners are disposed in or on the support. Said second fasteners either interact directly with the first fasteners, or the other end of the fastener engages them. The second fasteners may also be embodied as hollow profiles, eyes, hooks, holes, hook-and-loop fastener structures, magnets, clips, etc. Said fastener is preferably embodied as an elastic tape or cord between the knitted fabric and the support, so that the first fastener on the knitted fabric does not need to be positioned directly above the second in fastener on the support. Fastening can also be accomplished here if said fasteners are located somewhat far apart.1 Such spatial imprecision, which can always occur when a seat cover is being manufactured, is compensated for by the flexibility of the fastener.
1Translator""s note: The German word xe2x80x9cbeanstandetxe2x80x9d (meaning: to complain about something) that appears in this sentence is an obvious typographical error for xe2x80x9cbeabstandetetxe2x80x9d, which means to space or locate objects at a distance from one another. 
Both the first and the second fasteners preferably have an elongated configuration, thus permitting the fastener to be secured in the longitudinal direction. If the first and second fasteners continue to extend perpendicular to one another, there will still be some points at which the first fastener is located directly above the second fastener. Such points can be used to position fasteners. However, the fastener can also be embodied as a flexible but not elastic textile tape or textile cord, rubber band, woven tape, nonwoven fabric tape, or plastic tape, and perhaps a wire cord as well. Coil springs can also be used as the fasteners. The elastic fastener can be integrated directly on/in the first fastener on the knitted fabric or on/in the second fastener on the support.
The securing device of the invention is not merely suitable for fastening seat covers to seat frames; it is also suitable for fastening textile trim parts, design structures, insulation and filter parts to supports, for example in automotive interior applications.
The first and/or second fastener can also be embodied as a ferromagnetic material or magnet that interacts with the other complementary fastener (magnet, other pole/ferromagnetic material).
The elongated pocket formed by the two layers of fabric, which is used to insert the first fastener, may at some locations possess openings or perforations facing the support that can be used for fastening to the second fastener on the support or to a connector in the vicinity of said openings. Such openings also facilitate inserting the first fastener itself into the pocket.
In addition to securing the knitted fabric to the support by means of the fasteners, Velcro structures (hook-and-loop closures) can be provided to support the securing of the cover-for example in the area of curves or highly contoured parts in order to achieve a smooth, wrinkle-free design appearance at such locations.
Even though said joining technology cannot always be used due to the difficulty of solving the problems associated with it, the first and second fasteners can also be embodied as adhesive bonding sites that are joined to one another by applying an adhesive.